Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.sql.compile.RowCountNode

The result set generated by this node (RowCountResultSet) implements the filtering of rows needed for the and the . It sits on top of the normal SELECT's top result set, but under any ScrollInsensitiveResultSet. The latter's positioning is needed for the correct functioning of and in the presence of scrollable and/or updatable result sets and CURRENT OF cursors.

Field Summary

Modifier and Type	Field and Description
private ValueNode	fetchFirst If not null, this represents the value of a <fetch first clause>.
private boolean	hasJDBClimitClause True if the offset/fetchFirst clauses were added by JDBC LIMIT syntax.
private ValueNode	offset If not null, this represents the value of a <result offset clause>.

Inherited from org.apache.derby.impl.sql.compile.SingleChildResultSetNode:: childResult hasTrulyTheBestAccessPath

Constructor Summary

Access	Constructor and Description
pack-priv	RowCountNode(ResultSetNode The result set for which we want to get only a subset childResult, ResultColumnList The result columns we want rcl, ValueNode The offset, if any, in the result set offset, ValueNode The number of rows to inspect to get fetchFirst, boolean `true` if a JDBC limit syntax was used hasJDBClimitClause, ContextManager The context manager cm) Constructor for a RowCountNode

Method Summary

Modifier and Type	Method and Description
pack-priv void	generate(ActivationClassBuilder activation class builder acb, MethodBuilder method builder mb) Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.generate. Generate code.
private void	generateExprFun(ExpressionClassBuilder ecb, MethodBuilder mb, ValueNode vn)
public String	Returns: This object as a String toString() Overrides org.apache.derby.impl.sql.compile.FromTable.toString. Convert this object to a String.

Field Detail

fetchFirst	back to summary
private ValueNode fetchFirst If not null, this represents the value of a .

hasJDBClimitClause	back to summary
private boolean hasJDBClimitClause True if the offset/fetchFirst clauses were added by JDBC LIMIT syntax.

offset	back to summary
private ValueNode offset If not null, this represents the value of a .

Constructor Detail

RowCountNode back to summary

RowCountNode	back to summary
pack-priv RowCountNode(ResultSetNode childResult, ResultColumnList rcl, ValueNode offset, ValueNode fetchFirst, boolean hasJDBClimitClause, ContextManager cm) throws StandardException Constructor for a RowCountNode Parameters childResult:ResultSetNode The result set for which we want to get only a subset rcl:ResultColumnList The result columns we want offset:ValueNode The offset, if any, in the result set fetchFirst:ValueNode The number of rows to inspect to get hasJDBClimitClause:boolean `true` if a JDBC limit syntax was used cm:ContextManager The context manager

pack-priv RowCountNode(ResultSetNode childResult, ResultColumnList rcl, ValueNode offset, ValueNode fetchFirst, boolean hasJDBClimitClause, ContextManager cm) throws StandardException

Constructor for a RowCountNode

Parameters

childResult:ResultSetNode: The result set for which we want to get only a subset
rcl:ResultColumnList: The result columns we want
offset:ValueNode: The offset, if any, in the result set
fetchFirst:ValueNode: The number of rows to inspect to get
hasJDBClimitClause:boolean: true if a JDBC limit syntax was used
cm:ContextManager: The context manager

Method Detail

generate	back to summary
pack-priv void generate(ActivationClassBuilder acb, MethodBuilder mb) throws StandardException Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.generate. Generate code. Parameters acb:ActivationClassBuilder activation class builder mb:MethodBuilder method builder Annotations @Override Exceptions StandardException: Thrown on error

generate

back to summary

pack-priv void generate(ActivationClassBuilder acb, MethodBuilder mb) throws StandardException

Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.generate.

Generate code.

Parameters

acb:ActivationClassBuilder: activation class builder
mb:MethodBuilder: method builder

Annotations

@Override

Exceptions

StandardException:: Thrown on error

generateExprFun	back to summary
private void generateExprFun(ExpressionClassBuilder ecb, MethodBuilder mb, ValueNode vn) throws StandardException

toString	back to summary
public String toString() Overrides org.apache.derby.impl.sql.compile.FromTable.toString. Convert this object to a String. See comments in QueryTreeNode.java for how this should be done for tree printing. Returns:String This object as a String Annotations @Override

toString

back to summary

public String toString()

Overrides org.apache.derby.impl.sql.compile.FromTable.toString.

Convert this object to a String. See comments in QueryTreeNode.java for how this should be done for tree printing.

Returns:String

This object as a String